<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>clip-path实现border动画

    </title>
    <style>
        body,
        html {
            width: 100%;
            height: 100%;
            display: flex;
        }

        div {
            position: relative;
            margin: auto;
            width: 160px;
            line-height: 160px;
            text-align: center;
            font-size: 24px;
        }

        div::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            border: 2px solid gold;
            transition: all .5s;
            animation: clippath 3s infinite linear;

        }


        @keyframes clippath {

            0%,
            100% {
                clip-path: inset(0 0 95% 0);
            }

            25% {
                clip-path: inset(0 95% 0 0);
            }

            50% {
                clip-path: inset(95% 0 0 0);
            }

            75% {
                clip-path: inset(0 0 0 95%);
            }
        }

        .bg::before {
            background: rgba(255, 215, 0, .5);
        }
    </style>
</head>

<body>

    <div>Hello</div>
    <div class="bg">示意图</div>

</body>

</html>